Fears are growing of a large-scale measles outbreak as more parents than ever shun the controversial MMR vaccine.

Fears are growing of a large-scale measles outbreak as more parents than ever shun the controversial MMR vaccine.

Take-up of the MMR jab has fallen to a record low amid fears that it is linked to autism and bowel disorders. Tests being carried out on 26 suspected cases in London and the north east were widely expected to be confirmed as positive later this week.

Q: WHY SHOULD PARENTS ENSURE THEIR CHILDREN HAVE THE MMR JAB?

A: The Department of Health has repeatedly insisted the combined MMR vaccine, rather than single injections, is the best, most proven and most effective way to protect children against measles, mumps and rubella.

It contains five viruses for measles, mumps and rubella, and is given to children aged 12 to 15 months, with a booster before the age of five.

After one dose, it offers 100% protection from rubella, 95% protection from mumps and 92% from measles. After the second dose, 99% of children are protected.

Q: SO WHY THE CONTROVERSY?

A: Uptake of the vaccine was around 90% until a paper in the medical journal The Lancet alleged a link between the MMR jab and autism.

Controversy has since raged over whether there are any proven links between the vaccine and autism and inflammatory bowel disease.

There is anecdotal evidence from parents that their children have developed disorders after the jabs.

But the scientific community has examined the evidence time and time again and found no evidence of any link.

The Government commissioned several large-scale studies involving thousands of children and also found no link. The latest study carried out by the American Association of Paediatrics reviewed evidence from 1,000 different scientific papers and concluded there was no connection.

It also recommended single jabs should not be given as an alternative to MMR.

Q: WHAT IS THE RISK OF AUTISM AND BOWEL DISORDERS?

A: No reputable scientific evidence has found any link between the MMR vaccine or any other vaccine and autism and bowel disorders.

Q: WHAT ABOUT THE USE OF SINGLE VACCINES INSTEAD?

A: Measles, mumps and rubella vaccines have never been given separately in infancy in the UK. Before the introduction of MMR, measles was given to infants from age one and rubella was given to girls at age 10 to 13 years.

Medical opinion holds that there is no advantage in giving the vaccines singly because delay in giving a vaccine puts a child at greater risk of contracting a disease.

If the vaccines were given separately, health chiefs argue that it is likely many children would not complete the course and be unprotected for longer.

Single vaccines are also not licensed for use in this country and therefore have not been independently tested for potency and toxicity.

However, parents have strongly campaigned for the right to give their children single vaccines and many have travelled abroad or paid privately to obtain them.

Q: HOW SERIOUS ARE MEASLES, MUMPS AND RUBELLA?

A: The risk associated with the effects of the three disease are much greater than any potential risks of the vaccine.

Measles is caused by a virus and is highly infectious before a trademark red rash appears. Complications can include pneumonia and ear and eye infections and in a minute number of cases encephalitis (inflammation of the brain) may follow which can cause brain damage.

In less than one in 100,000 cases it can cause brain infection which can lead to death.

Mumps, also caused by a virus, does not usually cause severe problems in children but can lead to infertility in men.

Rubella, or German Measles, causes swelling of the lymph nodes and a rash in some sufferers. It is most serious when it strikes pregnant women as it can affect the foetus during the first three months of development and cause serious birth defects.

Q: WHAT HAPPENS IN THE REST OF THE WORLD?

A: No country in the world recommends immunisation against measles, mumps and rubella in three single vaccines rather than the combined MMR.

MMR has been given for nearly 30 years in the US and is considered very safe. Around the world, more than 500 million doses of the vaccine have been given in 90 countries.

However, you can get single measles jabs in France. The government recommends that babies in nurseries are given single measles vaccine from nine months if there is a risk of a measles outbreak.

Japan also uses single measles and rubella vaccines.

Q: WHAT HAPPENS IF PARENTS SHUN THE VACCINE?

A: If children do not have protection against the diseases, there is a risk of epidemics. This means not just measles outbreaks but the return of babies born with defects as a result of rubella in their mothers or children becoming deaf or hospitalised following mumps.

A DoH spokesman said that any take-up rate below 95% does not give "herd immunity".

He said: "This means it is not just children who have not had the jab who are at risk, but those below the age at which it is given."

Last year, there were 2,466 suspected cases of measles reported and 74 cases confirmed in England and Wales.